To stablish (sic) if lunar phases somehow do affect humans, an international group of researchers studied children to see if their sleeping patterns changed or if there were any differences in their daily activities. The results were published in Frontiers in Pediatrics.

IIRC there are various animals (mostly small and simple ones) whose behaviour is linked to the phases of the moon, so it wouldn't surprise me if the different levels of light during the night had some effect on humans. But of course, this would only apply to people living in the wild. Any such effects for most of us would be completely swamped by the universality of artificial lighting.

I knew an emergency services ambulance driver years ago who worked night shifts in the greater London area, and he swore that although they would get some sleep quite often, they never got any during full moons. He only worked nights and said he'd had years to verify this. I don't really see where the bias might be ... or what other effects might have been at play ...

"…all superstition is much the same whether it be that of astrology, dreams, omens, retributive judgment, or the like…[in that] the deluded believers observe events which are fulfilled, but neglect or pass over their failure, though it be much more common."